Hammermills

Abstract

In an upper portion of a housing is a material-receiving chamber below which is a lower portion that defines a comminution chamber. An apertured screen is disposed in the bottom of the latter for permitting the gravity discharge of material which has been comminuted. Mounted horizontally within the lower portion is a shaft, and that shaft is driven in rotation. A plurality of hammers project rigidly outward from the shaft with the hammers being arranged in an assembly which includes a plurality of hammer-carrying elements individually spaced successively along the shaft. The hammers on each element are circumferentially spaced successively around the shaft. Moreover, each hammer includes a material-impacting face of concave arcuate conformation in the plane of movement of the hammers.

It is claimed: 
     
       1. A hammermill which comprises: an upright housing including an upper portion which defines a material-receiving chamber and a lower portion which defines a comminution chamber;   an apertured screen disposed in the bottom of said comminution chamber for permitting the gravity discharge of material comminuted within said lower portion;   a shaft mounted horizontally within said lower portion;   means for driving said shaft in rotation;   and a plurality of hammers projecting rigidly outward from said shaft, said hammers being arranged in an assembly which includes a succession of hammer-carrying elements integrally carrying respective ones of said hammers and individually spaced successively along said shaft, each of said elements having an integral plurality of said hammers circumferentially spaced successively around said shaft, and each of said hammers including a material-impacting leading face of concave-arcuate conformation in the plane of movement of said hammers with each of said leading faces merging into a reversely-directed concave trailing face of the next successive one of said hammers on the same side of said shaft and with each set of said merging leading and trailing faces defining a single large concavity.   
     
     
       2. A hammermill as defined in claim 1 in which said shaft is mounted within said lower portion in a manner permitting its end-for-end reversibility. 
     
     
       3. A hammermill as defined in claim 1 in which, within each of said elements, respective different ones of said hammers on a given one of said elements are displaced from one another in the direction of said shaft. 
     
     
       4. A hammermill as defined in claim 1 which further includes a baseplate upon which said housing is mounted, and a plurality of concentrically-spaced rings which project downwardly from said baseplate for selective mounting upon the upper rims of respectively differently sized containers. 
     
     
       5. A hammermill as defined in claim 1 which further includes: a baseplate upon which said housing is mounted;   a dolly having horizontal arms projecting from respective uprights;   means for securing said baseplate to said arm;   means for adjusting the effective height of said arms;   means for adjusting the spacing of said housing from said uprights;   and in which said uprights slant downwardly and outwardly away from said baseplate.   
     
     
       6. A hammermill as defined in claim 1 which further includes a wear plate removably disposed over a portion of said screen beneath said material-receiving chamber and in a position to shield the portions of said screen and housing subject to maximum impact forces.   
     
     
       7. A hammermill which comprises: an upright housing including an upper portion which defines a material-receiving chamber and a lower portion which defines a comminution chamber;   an apertured screen disposed in the bottom of said comminution chamber for permitting the gravity discharge of material comminuted within said lower portion;   a shaft mounted horizontally within said lower portion;   means for driving said shaft in rotation;   a plurality of hammers projecting rigidly outward from said shaft, said hammers being arranged in an assembly which includes a succession of hammer-carrying elements integrally carrying respective ones of said hammers and individually spaced successively along said shaft, each of said elements having an integral total number of three of said hammers circumferentially equally spaced successively around shaft, and each of said hammers including a material-impacting face of concave-arcuate conformation in the plane of movement of said hammers;   and each of said faces merging into a reversely-directed concave face of the next successive one of said hammers on the same side of said shaft, the area of merger of said faces and said reversely-directed concave faces defining a comminution area and the distribution of said hammers and said elements around said shaft defining equilateral symmetry.   
     
     
       8. A hammermill as defined in claim 7 in which successive different ones of said hammers on any given one of said elements are displaced one from the next in the direction of said shaft. 
     
     
       9. A hammermill as defined in claim 7 which further includes: a base plate upon which said housing is mounted;   and a plurality of concentrically-spaced rings projecting downwardly from said base plate for selective mounting upon upper rims of respectively different sized containers.